1. Water is able to form hydrogen bonds because

oxyge

n has a valence

of 2.

the w

ater molecu

le is sh

...

the bonds t

hat hold to

g...

the oxyg

en atom in

a wa...

each of t

he hydro

gen ato..

0% 0% 0%0%0%0%

1. oxygen has a valence of 2. 2. the water molecule is shaped like

a tetrahedron. 3. the bonds that hold together the

atoms in a water molecule are polar covalent bonds.

4. the oxygen atom in a water molecule has a weak positive charge.

5. each of the hydrogen atoms in a water molecule is weakly negative in charge.

25

2.What gives rise to the cohesiveness of water molecules?

hydro

phobic inte

ractions

nonpolar covalent b

onds

ionic bonds

hydro

gen bonds

both A

and C

0% 0% 0%0%0%

1. hydrophobic interactions

2. nonpolar covalent bonds

3. ionic bonds 4. hydrogen bonds 5. both A and C

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3.Which of the following statements is true about buffer

solutions ?

1 2 3 4 5

0% 0% 0%0%0%

1. They maintain a constant pH when bases are added to them but not when acids are added to them.

2. They maintain a constant pH when acids are added to them but not when bases are added to them.

3. They maintain a constant pH of exactly 7 in all living cells and biological fluids.

4. They maintain a relatively constant pH.

5. They are found only in living systems and biological fluids.

25

Which molecule contains an amino functional group, but is not an amino acid?

A B C D E

0% 0% 0%0%0%

1. A2. B3. C4. D5. E

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5. Which of the following is false?

The higher t

he pH the m

...

pH affects th

e charge of..

.

A chan

ge in pH ca

n dena...

The pH scale

is lo

garit

hmic

1 and 4 are fa

lse

0% 0% 0%0%0%

1. The higher the pH the more H+ ions present

2. pH affects the charge of molecules

3. A change in pH can denature proteins

4. The pH scale is logarithmic5. 1 and 4 are false

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C=0Figure 4.4

6. What is the name of the functional group shown in Figure 4.4?

carb

oxyl

ketone

hydro

xyl

carb

onyl

aldehyde

0% 0% 0%0%0%

1. carboxyl 2. ketone 3. hydroxyl 4. carbonyl 5. aldehyde

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7. Which of the following statements is false?

As a ce

ll incre

ases i

n size

, i..

As a ce

ll incre

ases i

n size

, i..

In a cell,

membranes p

ro...

In a cell,

volume refe

rs to

...

In a cell,

it is m

ost desir

ab..

0% 0% 0%0%0%

1. As a cell increases in size, its SA increases by the square of the size increase

2. As a cell increases in size, its volume increases by the cube of the size increase

3. In a cell, membranes provide its surface area

4. In a cell, volume refers to the amount of cytoplasm

5. In a cell, it is most desirable to have a low surface area to volume ratio

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8. Of the following, which is probably the most common route for membrane flow in the

endomembrane system?

0% 0% 0%0%0%

1. vacuole → plasma membrane → nuclear envelope → smooth ER

2. Golgi → lysosome → ER → plasma membrane

3. nuclear envelope → lysosome → Golgi → plasma membrane

4. rough ER → vesicles → Golgi → plasma membrane

5. ER → chloroplasts → mitochondrion → cell membrane

25

9.Large numbers of ribosomes are present in cells that specialize in producing which of the following

molecules?

prote

ins

glucose

starch

es

stero

ids

lipids

0% 0% 0%0%0%

1. proteins 2. glucose 3. starches 4. steroids 5. lipids

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10.Tay-Sachs disease is a genetic condition called a storage disease that affects this cell organelle

Mito

chondria

ER

Golgi

Lyso

some

Vacuole

0% 0% 0%0%0%

1. Mitochondria2. ER3. Golgi4. Lysosome5. Vacuole

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11.Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?

riboso

me

lysoso

me

smooth

endoplasmic

ret..

.

mitoch

ondrion

contra

ctile va

cuole

0% 0% 0%0%0%

1. ribosome 2. lysosome 3. smooth

endoplasmic reticulum

4. mitochondrion 5. contractile vacuole

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12.These cell structures hold cells of tissues subject to mechanical stress (like the uterus) tightly together

peroxis

omes

desmoso

mes

gap ju

nctions

plasmodesm

ata

tight ju

nctions

0% 0% 0%0%0%

1. peroxisomes 2. desmosomes 3. gap junctions 4. plasmodesmata 5. tight junctions

25

13.A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and

mitochondria. It could be a cell from

a bacteriu

m.

an animal, b

ut not a

plant.

a plant, but n

ot an an

imal.

a plant or a

n animal.

any kind of o

rganism

.

0% 0% 0%0%0%

1. a bacterium. 2. an animal, but not a

plant. 3. a plant, but not an

animal. 4. a plant or an animal. 5. any kind of organism.

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14.Plasmodesmata in plant cells are most similar in function to which of the following structures in animal

cells?

glycoca

lyx

desmoso

mes

gap ju

nctions

extrace

llular m

atrix

tight ju

nctions

0% 0% 0%0%0%

1. glycocalyx 2. desmosomes 3. gap junctions 4. extracellular matrix 5. tight junctions

25

15.Which of the following is not associated with chloroplasts?

1 2 3 4 5

0% 0% 0%0%0%

1. DNA2. Photosynthesis3. stroma4. Respiration5. High inner

membrane surface area

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16.We used white blood cells as an example of an important cell type in the body several times when we discussed cell organelles and systems. What

roles(s) do white blood cells play in your body?

1 2 3 4 5

0% 0% 0%0%0%

1. They are involved in phagocytosis

2. They destroy invading bacteria and virus

3. Some white blood cells secrete antibodies

4. White blood cells patrol your body looking for invaders

5. All of the above

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17.If a plant cell is placed in a hypertonic environment

the tu

rgor p

ressure

of th...

the ce

ll will

swell b

ut won..

the enviro

nment will

ha..

the net m

ovement o

f wa..

.

0% 0%0%0%

a. the turgor pressure of the cell will increase;

b. the cell will swell but won't burst due to the presence of the cell wall;

c. the environment will have a greater solute concentration than is present inside the cell;

d. the net movement of water will be inside the cell.

25

18.Receptor mediated endocytosis

is a fo

rm of a

ctive

transp

...

is a fo

rm of f

acilita

ted dif...

describes t

he meth

od by...

is a

specia

lized ty

pe of e...

e) is a

way t

o transp

ort ...

0% 0% 0%0%0%

1. is a form of active transport; 2. is a form of facilitated

diffusion; 3. describes the method by

which vacuoles from the ER fuse to the membranes of the Golgi apparatus ;

4. is a specialized type of exocytosis;

5. e) is a way to transport specific substances from the environment in to the cell.

25

19.The membrane activity most nearly opposite to exocytosis is

plasmolysis

.

osmosis

.

facil

itated diff

usion.

phagocyto

sis.

active tr

ansp

ort.

20% 20% 20%20%20%1. plasmolysis. 2. osmosis. 3. facilitated diffusion.4. phagocytosis. 5. active transport.

25

20.The main problem with the Davson-Danielli model of membrane structure was that it:

did not acco

unt for t

he ...

phospholip

id fluidity w

a...

it place

d membrane pro

...

early electr

on micr

ogra...

nothing is

wro

ng with

t..

0% 0% 0%0%0%

a. did not account for the phospholipid bilayer

b. phospholipid fluidity was impossible

c. it placed membrane proteins in a layer on the membrane surface

d. early electron micrographs clearly did not support this model

e. nothing is wrong with the model, and it is accepted today by cell biologists

25

21.According to the fluid mosaic model of cell membranes, which of the

following is a true statement about membrane phospholipids?

1 2 3 4 5

0% 0% 0%0%0%

1. They can move laterally along the plane of the membrane.

2. They frequently flip-flop from one side of the membrane to the other.

3. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.

4. They are free to depart from the membrane and dissolve in the surrounding solution.

5. They have hydrophilic tails in the interior of the membrane.

25

22.If a membrane loses fluidiity

1 2 3 4 5

0% 0% 0%0%0%

1. It will lose its ability to regulate what enters and leaves the cell

2. It’s permeability properties will change

3. It will not be able to bring things into the cell by endocytosis

4. 2 and 35. All of the above

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23.The difference between simple and facilitated diffusion is that:

1 2 3 4

0% 0%0%0%

1. One goes from high to low concentration and the other goes from low to high

2. One requires a carrier molecule and the other does not

3. One requires energy and the other does not

4. One involves spontaneous movement and the other does not

25

24. The Na+/K+ Atpase pump

1 2 3 4 5

0% 0% 0%0%0%

1. Is a membrane protein2. Is an enzyme3. Has a binding site for

phosphate4. Depends on

conformational changes to pump ions

5. All of the above

25